Review – sharpening images with Nik Sharpener Pro
Review: Sharpening with Nik Sharpener Pro 3
A Photoshop plugin to sharpen images for screen and print
Version 3 of the sharpening plugin from Nik Software is reviewed.
We’ve used the previous version for several years as part of our printmaking workflow (this version is the same in functionality as you now get from the DxO Nik Collection).
Do updated features and more flexible fine control over sharpening make it worth the upgrade?
At Northlight we produce a lot of images, from large fine art prints, to small product photography shots for client’s websites. One of the key aspects of making our images look that little bit better is the correct application of sharpening. This varies with the size and purpose of the image.
Some work we specifically supply -without- sharpening, since we know some (but not all) clients are happy to take care of it for their own uses of the images.
For an example, let’s take one of our landscape images, taken on a camera like the 21MP Canon 1Ds Mk3. Even with such high resolution and top quality lenses, the raw camera file will need some slight sharpening when it is converted. This is often taken care of in the RAW conversion software such as Camera Raw in Photoshop (ACR) or DxO Optics Pro, which we use for some of our landscape work.
After working on an image for a while, we will often resize it for printing at a particular size. At this stage many people print their images and that’s done with it.
However, printing is a process that inherently loses image detail. This varies with printing technology and paper types. By applying sharpening to an image you are trying to give the greatest -impression- of sharpness and detail. The amount (and type) of sharpening required depends on many factors, such as the size of the print, the type of image, the particular printer, and your personal taste.
Sharpening can even vary across different areas of a print – as I’ll show in an example below. All these variable mean that there is no ‘one size fits all’ approach to sharpening for output (as it is sometimes referred to).
I make a lot of prints, but I’d find it difficult to remember all the various options and settings if I had to use just the normal tools in Photoshop.
We’re looking at the software working as a Photoshop plugin on a Mac here, but it works just fine under Windows. It also works with Apple Aperture (May 08 – also with Lightroom 2.3).
It’s possible to use the filter as a smart filter in Photoshop. This allows you to go back and re-adjust filter settings. Both the Sharpener Pro 3.0 RAW Presharpener and Output Sharpener filters can be applied as Actions and as part of a batch process within Adobe Photoshop.
The software is available in a range of bundles and upgrade options. You can order by download or there are boxed versions.
I’m concentrating on the output sharpening in this review, rather than the input or RAW image sharpening offered by the software – this works in a similar way to the print/display sharpening I’ll describe below, but I’m going to wait until I’ve got a really good example of its use before describing it.
Display (web) Sharpening
I’ll start with a simple web example – this is the box shot that’s used at the head of this review.
I’ve taken the picture from Nik’s own site and opened it in Photoshop.
I’ve cropped it to how I want and selected Nik Sharpener Pro V3 in my filters list.
The basic settings allow me to view the image in different ways and adjust the amount of sharpening.
I’ll come to many of the advanced features later, but for ‘display’ output (such as web images) I’m really only wanting to adjust the amount of sharpening.
Do remember that many of the images you see in this article have been resized and resampled to show on a web page. They are also compressed JPEG images, so easily lose detail.
The image to the right, is an unreduced screen grab showing how applying a modest amount of sharpening (34% in this case) alters the look of the box image.
Once again, I’m of the opinion that Nik could do with improving the sharpening of some of the images on their own site ;-)
Roll your mouse over the image to see my preferred version – remember that a lot of sharpening settings depends on your own taste as to what is best. Note too, that sharper images produce larger JPEG files, so this may be a factor.
Sharpening for print
The following examples are based on a number of images that I’ve recently been printing.
The first one is of an interesting sky in Colorado last fall (Hwy 131 south of Toponas). It was taken on a Canon 1Ds3 with a 14mm lens. I’ve spent a while with masked curve adjustment layers to get the tonality of the sky the way I want it. The original colour file was converted to black and white with Nik Silver Efex Pro (see our recent review of Silver Efex)
I’ve flattened all the layers and set the image size to the print size I want – in this case I’ve just upped the DPI (resolution) of the file. This reduces the size of print if not resampled, since I wanted it to fit it on an A3+ piece of paper (13″x19″) and print it on our Epson 7880 [review].
The file opens up in the Sharpener Pro window. In the examples below I’m working on a 23″ display.
I need to set the type of sharpening required.
- Display – Sharpens for display devices such as monitors and projectors.
- Continuous Tone – Sharpens for continuous tone printers such as prints found at photographic labs using silver-halide based papers and dye-sublimation printers.
- Halftone – Sharpens for halftone printers such as large web or sheet-fed presses.
- Inkjet – Sharpens for inkjet printers such as Canon, Epson, and HP.
- Variable Tone – Sharpens for printers that use a hybrid of inkjet and halftone screening techniques.
The ‘Inkjet’ setting will work for the Epson 7880 I’m going to use to print this image.
I also need to select the paper type, since surfaces like canvas lose a lot more of your image’s detail when printed, than a paper such as the lustre finish I’m testing.
It’s also important to consider the viewing distance for your print.
In this example I’m leaving it set to ‘Auto’.
The levels of sharpening will thus be based on the print size for your image (another reason to set the print size before sharpening).
Many of our large prints (30″x40″ for example) are supplied to commercial premises.
Ideally, we like to know where they are going to be placed, since you can sharpen a print much more if it is going to be viewed from no closer than 10 feet.
Conversely, much less sharpening is allowable if people are going to pass within a few feet of the print
There is an article I wrote some time ago about the importance of viewing distance and what print resolutions will suffice.
It’s also important to set the printer resolution correctly, since a courser ink dot pitch (DPI – dots per inch) needs a different amount and type of sharpening.
For our 7880 printer, a setting of 1440×1440 is appropriate for the printer driver settings we’re using.
Remember that printer resolution 1440 DPI is not the same as the image resolution used for the print, in this case 310 PPI (pixels per inch – often erroneously referred to a DPI).
Working on your image
There are a number of different ways of looking at your image to decide on appropriate settings.
You can have before/after views like this
or have a split screen version.
If you are looking at the whole picture, it’s very difficult to see the effects of fine adjustments on the image.
There is in this case a 100% ‘Loupe’ view that shows detail of the sharpening.
It’s important to remember that an image correctly sharpened for print will almost certainly look far too sharp on a monitor.
It’s this difference, caused by the way that printing softens images that most often catches out people trying to sharpen images ‘by hand’.
It takes a lot of experience to know when your image risks looking ‘over sharpened’ in parts.
One of the things I like about using this software is that it gives me a good starting point to work from.
Remember too, that a print intended for a location where no-one is expected to get closer than say 10 feet, can be sharpened appreciably more than one where people brush against it.
We often supply large prints for commercial use, and knowing where they will be positioned is an important aspect of providing an optimal print.
Of course, you can zoom in with the main display area, and in this case the Loupe changes to a ‘Navigator view.
The two screen shots below, show the navigator display and part of the main image (both at 100%).
In the simple display example earlier, I just altered the overall strength of the sharpening.
One of the strengths of Nik Sharpener Pro 3 is the way that you can fine tune the sharpening.
Notice the three settings Structure, Local Contrast and Focus. These alter the sharpening at different scales on the image.
Structure is an easy one to show.
In the example below I cranked it up, and you can see that the structure of the clouds is greatly enhanced.
Equally, local contrast (when turned down) is clear to see.
Nik Software describe the settings as:
- Structure — Controls the fine details and textures within the image. Increasing this slider emphasizes fine details throughout the image while decreasing this slider reduces the appearance of fine details for smoother surfaces.
- Local Contrast — Controls local contrast throughout the entire image. Increasing this slider will increase the edges of small objects throughout the image while decreasing this slider will lower the contrast of edges, applying a diffusing effect.
- Focus — Controls the adaptive sharpening of fine image details and large areas of the image. Increasing this slider will increase the overall strength of the adaptive sharpening and decreasing this slider will decrease the adaptive sharpening, applying a slight blurring effect to the image.
Whilst these effects are very useful, I’d caution against using them for major changes in the look of your image.
I take the approach of producing a ‘master file’ of an image at its native resolution, and then producing specific sharpened versions (resampled/resized if need be) at different sizes.
I prefer to do any major alterations to the look and feel of the image to the master file. This ensures a consistency in my printing whether I’m producing a version at A4 or 30″x20″.
Once I’ve decided on the various settings I want, I can select OK and the software sharpens my image.
That’s not always the end of it though.
You can either apply the filter to a copy of the layer sharpened, or to the original layer itself.
This is selected in the settings panel.
There is a soft proofing view available as well, which tries to simulate how the sharpening will look as a print, but since this doesn’t include soft proofing of paper profiles, you should try and ignore the colour part of the image and just look at sharpness.
In a strongly coloured image, such as below, this is not always that easy.
The horizontal bar above gives an idea of scale for the printed image.
In the example below you can see the sharpener tools that appear if you select ‘Brush’ rather than ‘OK’ back in the main window.
Note the black layer mask associated with the new sharpened layer.
This allows me to paint in sharpening to areas of the file that need it.
However, didn’t I say that all images need sharpening before printing?
Yes, but not necessarily -all- of the image.
I can use the paint brush to select areas of the file that need the sharpening, and in this instance it isn’t the sky.
Firstly, clouds often don’t benefit from sharpening, and secondly sharpening can easily exacerbate noise in blue skies.
For this image, I’m just going to apply sharpening to some of the distant mountains and some texture in the foreground.
The mask now shows the areas I’m applying sharpening.
I’ve quite a few pictures with mountains and bits of snow on them. In the past, I’ve found that distant small patches of snow (just a few tens of pixels of solid white) were sharpened too much compared with their surroundings. V3.0 is better in its handling of such detail, but the skyline is one area I always check for sharpening artefacts that would be overly visible in a print.
The net effect is that I can make the print feel a lot sharper than it is and emphasise different areas. Another example would be sharpening some areas of a face less than others.
The brush/mask technique is useful for some sorts of images, but the plug-in has plenty more advanced tricks up its sleeve that help fine-tune the look of your print.
Using the painting/mask approach works well for images with clearly delineated areas that need sharpening, but what about ones like below?
The fine detail in all the twigs and branches can easily end up over sharpened compared to other parts of the image. There are also too many of them for me to start painting in effects.
The example I’ll use, has slightly clearer areas of different sharpening requirements.
The pictures are from Rutland Water in the UK earlier this year and capture the views at sunset on a rather chilly day.
I’ve used some of these images in our recent reviews of the Epson 7880 and DxO Optics Pro.
The intense colours give a pretty good feel (as a print) for what it was like there, although when printed, some of the intensity seen here is lost. This is another aspect of how I prepare images to make good prints – not necessarily to look their best on screen.
The default levels of sharpening produce slight halos around the twigs against the dark blue sky.
This is easily visible in a print and I’d like to turn it down a bit.
As before, remember that effects are -much- more noticeable in the screen at 100% than they are in a print.
However, I’ve tested this one and the effect is far too obvious for my liking.
One way of localising adjustments is to use the Control Point option.
This is one of Nik Software’s ‘big things’ where it’s known as ‘U Point’.
I’ve covered some uses of this in the review of Nik Silver Efex Pro, where it allows you to vary effects in some quite complex ways.
This description from Nik Software:
“The U Point technology powered Control Points let you identify and isolate objects within a photograph by placing a Control Point on the object or area to be affected. By analysing the colour, tonality, detail, and location, the Control Point automatically determines where and how to apply certain effects, based on your needs.”
The tree branches are mostly in one part of the image, so I’ll place a control point.
I’ve picked a branch and using the adjustment sliders turn down the focus (or fine detail) slider.
The control point has Radius, intensity, structure, local contrast and Focus adjustments.
These are just like the global ones I’ve shown before.
The picture to the right shows the Focus adjustment ‘F” turned right down.
Note that the different sliders work in different ways – for this image, the Focus slider ‘fixed’ the effect the most – there is a fair bit of trial and error here to get optimal results.
You can have a number of control points and fine tune different parts of your image.
There is an option to show the ‘area of influence’ too.
I tried several places for the control point and couldn’t get things quite right.
I wondered if instead of the twigs being sharpened, it was the solid bits of blue in the sky?
Fortunately there are more options.
In addition to control points there is another mode of selection – by colour.
An eye-dropper can be used to sample a colour range for applying sharpening.
Notice how the noise in the sky is increased too.
The small tiles of colour are indicative of the colour you’ve selected, however the plugin is fully colour managed and had no problem if I was using a large colour space, such as ProPhoto in this example.
Since you can only control levels of sharpening by colour, I’ve altered global settings and lowered the strength for the blue.
Compared to the earlier version of Sharpener, version three seems to require less intervention and fine tuning to get very good results.
Since reviewing this package, we’ve switched over to V3.0 for most of our fine art print work. We’ve used Nik Sharpener Pro V2 for a while – there are many more examples of the use of sharpening in the review of that version.
The default values suggested by the software seem more appropriate that before, although as with any global sharpening technique, you still need to check images for artefacts that might show in a print.
You will need to experiment with the package, and probably need to do a few small test prints to get the hang of sharpening. Despite the help this package offers, you will get consistently better results after a few trials.
The software allows you to save chosen sets of alterations as presets, but I’d say that you should take care to note why certain settings work with different image elements and sizes, rather than hope that the software will spare you the effort of thinking about what you are doing.
If you normally print at A3+ for example, take a small section of a good image and test print a series of patches (at the same scale as the full image) with a number of different settings. Remember that what you see on the screen is only an intermediate stage in getting to a good quality print.
We’ve not covered the RAW camera file sharpening here(more strictly sharpening for the output of a RAW converter), since it’s very difficult to show differences in images, although a few quick tests show that using the selective RAW sharpening may be of use when you need to enlarge a file by quite a lot.
Our tests a few years ago showed that selective sharpening after raw processing (where no sharpening had been applied) could yield improvements in very large prints. I’ll perhaps revisit this, the next time I have to produce a very big print.
The software is not cheap, but for our business, getting that extra bit of quality in our prints is important.
Easy to use package offering sharpening options to improve the look of printed and display images.
Sharpening options are also available for sharpening RAW camera files after processing by other software.
The software is runs on Mac and PC and is available in a number of bundles and upgrade options.
System requirements (V3)
- Mac OS 10.4 and 10.5 or later
- G4, G5, Intel Core Solo, Intel Core Duo, Intel Core 2 Duo, Intel Xeon
- 512 MB RAM
- Adobe Photoshop CS2 through CS4, Adobe Photoshop Elements 4.0 and 6.0; other Adobe Photoshop plug-ins compatible applications*
- Apple Aperture 2.1 or later
- Windows 2000 Professional, Windows XP, Windows Vista (32-bit)
- Pentium III 1GHz or better
- 512 MB RAM
- Adobe Photoshop 7 through CS4, Adobe Photoshop Elements 2.0 through 6.0; other Adobe Photoshop plug-in compatible application*
* Nik Software product filters are developed to integrate into many popular image editing applications that support the Adobe plug-in architecture and there are numerous software applications that accept Adobe plug-in compatible filters. Please consult your image editing application’s documentation for compatibility and installation instructions for 3rd-party plug-ins.
May 2008 – now works with Lightroom 2.3
Dec 2015 – the software is part of the Google Nik Collection
2019 – the software is part of DxO Nik plugins. There is a free demo of the Nik software available
- OSX 10.7 onwards,
- Win Vista,7,8
- PS CS4 onwards, LR3 onwards
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